For many years, metal vapor vacuum arc (MeVVA) ion source systems have been used to produce beams of metal ions for injection into Electron Beam Ion Trap (EBIT), particle accelerators, and for ion implantation applications. Such systems are useful for implanting ions into surfaces of objects, or for applying metallic coatings to large substrate areas, such as the application of titanium nitride protective coatings to cutting tools, to name but a few.
Past MeVVA designs utilize a three wire system construction requiring a cathode, an anode, and a trigger wire as separate components and all in close proximity in a vacuum arc head. Some of these systems employ a low voltage (˜12 mf) capacitor chargeable to 200-500 VDC that is hard-wired to both the anode and cathode.
Triggering the discharge on the three wire systems is accomplished via the third wire, which supplied a low current pulse of high voltage (10-30 kV), placed in vacuum near the anode and cathode of the MeVVA ion source head. Limitations of this type of design are a large arc jitter, on the order of about 3-6 ms, and a relatively short operation life, where the number of shots before a rebuild is necessitated is relatively small, ˜100,000 shots. A failure mode occurs when the cathode sample material sputters sufficiently to coat the insulator of the trigger pin, causing an electrical short that renders the system to a non-triggerable state. Three wire, water cooled, multi-element (selected by moving parts within the vacuum enclosure) MeVVA systems have been previously built by other workers.
There is, therefore a need for a MeVVA ion source system having greater reliability, longer lifetime, and with less jitter on the ion source production.